The subject matter disclosed herein relates to fuel dispensing systems and, in particular, to embodiments of a sealing device to prevent exposure of electronics to fuel vapors in fuel dispensing systems.
Fuel dispensing systems transfer fluid (e.g., gasoline, diesel, etc.) from storage tanks to receptacles (e.g., a fuel can and/or a fuel tank on a vehicle). These systems include a dispensing unit that incorporates, in some examples, nozzles, grade selectors, and payment components that allow consumers to complete transactions at the dispensing unit. The dispensing unit also includes various types and configurations of electronics to facilitate operation of these various devices and features. However, these electronics are often susceptible to damage from, if not wholly incompatible with, vapors that are the by-product of the fluids that flow through the dispensing system.
Designs for the dispensing unit attempt to avoid exposing the electronics to the vapors. These designs often use separate compartments to segregate the electronics from any fuel-handling components (e.g., meters, pumps, etc.). In many cases, however, the electronics must communicate with one or more of the fuel-handling components. This requirement necessitates openings that permit wiring to penetrate through the walls that form the compartments, e.g., to couple a flow meter in one compartment to a control circuit in another compartment. Typically the openings are large enough to accommodate the wiring and, in some examples, to allow conduits (e.g., tubing) that insert into the opening. The conduits provide a pathway for the wiring between the various components.
Wiring that extends through the compartmentalized construction can permit vapors to migrate through the openings and conduits into the electronics compartment. As dispensing units add new features and functions, more wires and, accordingly, more openings are necessary. The structure that results is, in effect, very porous to vapor. Moreover, the porosity is made worse due to tolerance stack-ups and other manufacturing considerations that require openings that are larger than the wires and/or conduits.
To address the effective porosity, dispenser units incorporate seals that install about the outer surfaces of the wires and/or conduits. These seals are in place to prevent vapors from migrating into the electronics compartment through gaps between the outer surface of the conduit and the inner surface of the openings.